Harlem's not Harlem anymore?

Rapper Freestyle set the tone as Sergio and Ashley continued their quest through Harlem. This time they explored the area's heartbeat: 125th Street.

There's still a huge hip-hop and urban presence, but many fear Harlem's history is being lost because of gentrification. Congressman Charlie Rangel describes Harlem when he first got into office in 1971.

"The Harlem that I had when I was in congress was so many deteriorated buildings, rats, roaches, crime was high. Everybody knew somebody that got mugged," Rangel said.

Rangel said since then crime has gone down and new buildings have popped up. But he says the biggest challenge is affordable housing.